<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <style type="text/css">
      html { background-color: grey; }
      div { display: inline-block;
            font-size: 30px;
            line-height: 60px; /* Ensure space for underbar */
            border: 1px solid white;
            padding: 2px; /* 10% error allowed in char selection */
            background-color: black;
            color: red; }
    </style>
  </head>
<body>
  <div>
    <math xmlns="http://www.w3.org/1998/Math/MathML">
      <mphantom>
	<munder>
	  <mn>1</mn>
	  <mo>&#x332;</mo>
	</munder>
      </mphantom>
    </math>
  </div>
</body>
</html>
